On Sun, Dec 10, 2017 at 10:50:17PM -0500, Theodore Ts'o wrote: > CONFIG_LOCKDEP_CROSSRELEASE and CONFIG_LOCKDEP_COMPLETIONS can result > in a large number of false positives because lockdep doesn't > understand how to deal with multiple stacked loop or MD devices. > > Until someone can figure out how to automatically add annotations to > all file system and storage devices --- hopefully without forcing > developers to insert a large number of calls to undocumented lockdep > macros into the the loop device, every single file system, and every > single device-mapper backend --- let's add an option to allow these > lockdep features to be disabled. Otherwise, many file system > developers will disable LOCKDEP entirely since it results in far too > many false positives when trying to use xfstests. Note --- this is going to be in the ext4 git tree because otherwise using Lockdep would greatly interfere with ext4 development --- and I'd prefer not to completely give up on Lockdep as a lost cause. As such, it will appear in linux-next. I'll drop it from the ext4 git branch before I send a pull request to Linus, unless I get an OK for me to merge this patch to mainline via the ext4 git tree. Cheers, - Ted
